Tin-containing dopant compositions, systems and methods for use in ion implantation systems

Abstract

A novel method and system for using certain tin compounds as dopant sources for ion implantation are provided. A suitable tin-containing dopant source material is selected based on certain attributes. Some of these attributes include stability at room temperature; sufficient vapor pressure to be delivered from its source supply to an ion chamber and, the ability to produce a suitable beam current for ion implantation to achieve the required implant Sn dosage.

The invention claimed is: 
     
       1. A method for using Sn containing dopant material for an ion implantation process, comprising the steps of:
 storing a Sn containing dopant source in a storage and delivery container; 
 the Sn-containing dopant source characterized all of the following attributes: (i) stability during storage and delivery; (ii) a vapor pressure of greater than or equal to 20 Torr at room temperature (25° C.); (iii) existing as a liquid at room temperature; and (iv) comprising Sn and a carbon atom; 
 withdrawing the Sn containing dopant source in the vapor phase from the storage and delivery container; 
 flowing the vaporized the Sn containing dopant source; and 
 introducing the Sn-containing dopant source vapor to an ion source chamber. 
 
     
     
       2. The method of  claim 1 , wherein said Sn-containing dopant source has a representative formula R n SnX 4-n  where n=1 to 3, R is a functional group comprising carbon (C) and hydrogen (H) and X is a halogen selected from the group consisting of F, Cl, Br and I. 
     
     
       3. The method of  claim 1 , wherein said Sn-containing dopant source has a representative formula R n Sn where n=4, R is a functional group comprising carbon (C) and hydrogen (H). 
     
     
       4. The method of  claim 1 , wherein the Sn-containing dopant source has the representative formula R n Sn(C y X z ) 4-n  where n=1 to 3, X is a halogen selected from the group consisting of F, Cl, Br and I, and R comprises C and/or H atoms, and the values of y and z vary depending on the C—C bonding such that each atom in the C y X z  group has a closed shell of valence electrons. 
     
     
       5. The method of  claim 1 , wherein the Sn-containing dopant source has the representative formula R n Sn(C y X z ) 4-n  where n=0 or 4, X is a halogen selected from the group consisting of F, Cl, Br and I and R comprises C and/or H atoms, and the values of y and z vary depending on the C—C bonding such that each atom in the C y X z  group has a closed shell of valence electrons. 
     
     
       6. The method of  claim 1 , wherein the Sn-containing dopant source material has the representative formula R 4-y-z  Sn(OR′) y X z  where z=0 to 3, y=1 to 4, X is a halogen (X=F, Cl, Br, I) and R and R′ contains a mixture of C and H atoms. 
     
     
       7. The method of  claim 1 , further comprising introducing a diluent species into the ion source chamber. 
     
     
       8. A source supply for a Sn dopant gas composition comprising:
 a Sn-containing dopant source characterized by all of the following attributes: (i) stability during storage and delivery; (ii) a vapor pressure of greater than or equal to 20 Torr at room temperature (25° C.); (iii) existing as a liquid at room temperature; and (iv) comprising Sn and a carbon atom; 
 a delivery and storage device for maintaining the Sn-containing dopant source in a pressurized state within an interior volume of the device, said delivery device in fluid communication with a discharge flow path. 
 
     
     
       9. The source supply of  claim 8 , said delivery and storage device comprises an adsorbent onto which said Sn-containing dopant source is adsorbed thereon during storage. 
     
     
       10. The source supply of  claim 8 , said delivery and storage device comprising a vacuum actuated check valve. 
     
     
       11. The source supply of  claim 8 , wherein said Sn-containing dopant source is stored in the delivery and storage device in a gas phase. 
     
     
       12. The source supply of  claim 8 , wherein said Sn-containing dopant source is stored in the delivery and storage device in a liquid phase in equilibrium with a gas phase, wherein said Sn-containing dopant source exerts a sufficient vapor pressure to allow flow from the storage and delivery device into an ion chamber that is operably connected to said storage and delivery device. 
     
     
       13. A Sn-containing dopant composition for use in an ion implantation process, comprising:
 a Sn-containing dopant source material characterized by all of the following attributes: (i) stability during storage and delivery; (ii) a vapor pressure of greater than or equal to 20 Torr at room temperature (25° C.); (iii) existing as a liquid at room temperature; and (iv) comprising Sn and a carbon atom. 
 
     
     
       14. The Sn-containing dopant composition of  claim 13 , wherein said Sn-containing dopant source material has a representative formula R n SnX 4-n  where n=1 to 3, R is a functional group comprising carbon (C) and hydrogen (H); and X is a halogen selected from the group consisting of F, Cl, Br and I. 
     
     
       15. The Sn-containing dopant composition of  claim 13 , wherein said Sn-containing dopant source material has a representative formula R n Sn where n=4 and R is a functional group comprising carbon (C) and hydrogen (H). 
     
     
       16. The Sn-containing dopant composition of  claim 13 , wherein the Sn-containing dopant source material has the representative formula R n Sn(C y X z ) 4-n  where n=1 to 3, X is a halogen selected from the group comprising of F, Cl, Br and I; and R comprises C and/or H atoms, and the values of y and z vary depending on the C—C bonding such that each atom in the C y X z  group has a closed shell of valence electrons. 
     
     
       17. The Sn-containing dopant composition of  claim 13 , wherein the Sn-containing dopant source material has the representative formula R n Sn(C y X z ) 4-n  where n=0 or 4, X is a halogen selected from the group consisting of F, Cl, Br and I, R comprises C and/or H atoms, and the values of y and z vary depending on the C—C bonding such that each atom in the C y X z  group has a closed shell of valence electrons. 
     
     
       18. The Sn-containing dopant composition of  claim 13 , wherein the Sn-containing dopant source material has the representative formula R 4-y-z  Sn(OR′) y X z  where z=0 to 3, y=1 to 4, X is a halogen (X=F, Cl, Br, I) and R and R′ contains a mixture of C and H atoms. 
     
     
       19. The Sn-containing dopant composition of  claim 13 , wherein said Sn-containing dopant composition is selected from the group consisting of F 3 SnCH 3 , F 3 SnCH═CH 2 , (CH 3 ) 2 Sn(CF 3 ) 2 , F 3 SnCH 2 CH 3 , (CH 3 ) 3 SnCF 3 , (CH 3 ) 3 SnCF 2 CF 3 , (CH 3 ) 3 SnCF═CF 2 , F 2 Sn(CH 2 CH 3 ) 2 , F 3 SnCH 2 CH 2 CH 2 CH 3 , Sn(CH 3 ) 4  and Sn(CF 3 ) 4 . 
     
     
       20. The Sn-containing dopant composition of  claim 13 , wherein said Sn-containing dopant source material is selected from the group consisting of F 3 SnCH 3 , F 3 SnCH═CH 2 , (CH 3 ) 2 Sn(CF 3 ) 2 , F 3 SnCH 2 CH 3 , (CH 3 ) 3 SnCF 3 , (CH 3 ) 3 SnCF 2 CF 3 , (CH 3 ) 3 SnCF═CF 2 , F 2 Sn(CH 2 CH 3 ) 2 , F 3 SnCH 2 CH 2 CH 2 CH 3 . 
     
     
       21. The Sn-containing dopant composition of  claim 13 , wherein said Sn-containing dopant source material is utilized in combination with an adsorbent-based system. 
     
     
       22. The method of  claim 1 , wherein the Sn-containing dopant source has the representative formula R n Sn(C y X z ) 4-n  where n=0 to 4, X is a halogen selected from the group consisting of F, Cl, Br and I, and R comprises C and/or H atoms, and the values of y and z vary depending on the C—C bonding such that each atom in the C y X z  group has a closed shell of valence electrons.